U.S., Mexico to build border database

By Allan Holmes

Jun 16, 1996

The United States and the government of Mexico signed a ground-breaking agreement last month that clears the way for the two countries to create a standardized and comprehensive electronic database of maps of the neighboring countries' shared border.

The U.S./Mexico Border Aerial Photography Initiative will create a geographic information system (GIS) that will allow scientists to better track issues affecting human health, the environment, wildlife habitats and natural resources that do not recognize the nearly 2,000-mile political boundary separating the United States and Mexico.

"This really is a landmark agreement," said Richard Wright, a geography professor at San Diego State University. "There's really nothing quite like it."

The agreement, which took more than a year to put together, was necessary to update old U.S. Geological Survey maps, to complete aerial photography of the entire border and to begin studying border issues in more depth.

"We just couldn't afford to map up to the border and then leave it blank on the other side," said Ken Osborn, assistant chief of program management at USGS and the head of the border mapping program.

Under the agreement, which received support from the 1994 North American Free Trade Agreement because it focused attention on land use and pollution along the border with Mexico, USGS will take aerial photographs this year of a 100-mile strip of land running the length of the border. USGS will use infrared film to produce detailed images of vegetation and water resources that black-and-white film cannot.

The Instituto Nacional de Estadistica, Geografia e Informatica (INEGI), USGS' counterpart in Mexico, will be responsible for the 100-mile strip of land south of the border. Because of a shortfall in funds, INEGI will take infrared photographs of about one-third of the border region, with the rest photographed with black-and-white film.

As funding becomes available from such worldwide organizations as the World Bank, INEGI will eventually take infrared photographs of the entire border region.

In fiscal 1997, the photographs will then be scanned into a database using a standard format, which will be corrected for distortion and made available for public use.

The digitized maps will make it much easier for scientists to study environmental issues, such as air and water pollution; land management issues, such as water use; and searches for oil and gas reserves and mineral deposits.

For example, San Diego shares the same airshed and watershed with Tijuana, Mexico, as does El Paso, Texas, and Ciudad Juarez, Mexico. Measurements of particulates in the air and water can be overlaid on the digital maps to study pollution's point of origin.

Wright, chairman of the Transboundary Resource Inventory Project, a 2-year-old organization supported by local and state governments and universities near the U.S.-Mexican border, said the initiative will be invaluable in helping TRIP develop a uniform environmental inventory of the border region.

"This is a terrific first step in getting up-to-date maps that don't stop at the border," said Charles Palmer, manager of the Texas Natural Resources Information System, which distributes maps for wildlife and land use in Texas. "Many of our maps just drop off into outerspace when you reach the border."

To come to an agreement on the mapping program, USGS and INEGI had to overcome many obstacles. USGS typically uses a scale of 1:24,000 in its aerial photography, while INEGI's standard scale is 1:50,000, meaning it took four USGS maps to cover the same area as one INEGI map. The agencies agreed to use a 1:40,000 scale.

In addition, Mexico had to agree to change its policy on the release of information. The Mexican government holds copyrights to information such as maps and sells it to individual users, who agree not to distribute it. USGS maps are public information and are freely distributed.

Also, USGS had to overcome some skepticism from Mexican officials that the U.S. government would not use the information to influence economic, environmental and land-use policies along the border to the detriment of Mexico.

Osborn said Canadian officials are interested in conducting a similar program along the U.S.-Canadian border.